The present disclosure, according to specific example embodiments, generally relates to improved methods for characterizing the performance of fluids. In particular, the present disclosure relates to a high temperature, high-pressure fluid filtration test apparatus, and associated methods of use.
In drilling wells for production of hydrocarbons from underground formations, drilling mud typically cycles through a well bore during drilling. In addition to driving a drill motor and cleaning a drilling bit, the drilling mud also provides a column of fluid that exerts pressure on the formation pierced by the well bore, which prevents or reduces fluid from a reservoir or formation from entering the well bore. In addition, drilling mud may infiltrate the formation in the region surrounding the well bore (the near well bore region).
A problem often encountered during subterranean treatments is the undesired loss or leak off of fluid into the formation. This undesired loss or leak off is commonly referred to as “fluid loss.” Such treatments include, but are not limited to, drilling operations, cleanup operations, workover operations, completion operations, stimulation treatments (e.g., fracturing, acidizing), and sand control treatments (e.g., gravel packing). In fracturing treatments, fluid loss into the formation may result in a reduction in fluid efficiency, such that fracturing fluid cannot propagate the fracture as desired.
Fluid loss into the formation may result from a number of downhole conditions, such as high-formation permeability, overbalance pressures, perforated or open-hole intervals in the well bore, and large differential pressures associated with differential segregation in wells completed in a multilayer reservoir. In some instances, the fluid loss may be into a low-pressure portion of the formation due to overbalance pressures, for example, where a well is completed in a multilayer reservoir.
Traditional methods of characterizing the performance of fluids have involved a high pressure, high temperature filtration test. High Pressure, High Temperature (HPHT) filtration tests are used to measure filtration behavior of water or oil based drilling fluids at elevated temperatures, usually according to the specifications of the American Petroleum Institute (API). These tests are typically time intensive due to their setup requirements, testing protocol, and clean-up operations. As drilling rig time, space on offshore rigs, and personnel become more expensive, there exists a need for a method of testing fluids that requires less manpower and time.